Combined Sewer Overflows (CSO)

Sign up to receive notifications of combined sewer overflows

While we work to minimize CSO’s as much as we possibly can with current funding, we understand that notification of when we discharge is important to many downstream communities and other watershed users. Sign up now to receive notification when a CSO discharge occurs. We will notify you within two hours of the start of a discharge and update every eight hours.

Want to know more about how we work to reduce CSO events? Check out our High Flow Management page for a detailed review or contact a member of the Lowell Regional Wastewater Utility.

Click here to view the CSO Notification Plan

1Recent Overflow Notification

This is a public notification that discharges of blended wastewater and/or untreated Combined Sewer Overflows (CSOs) were active at the Lowell Wastewater Utility and/or its diversion structures on 9/18/23 starting at approximately 8/19/23 1:13 pm. These overflows have ceased as of 9/20/23 3:11 am. 

It is recommended to avoid contact with these water bodies for 48 hours after the discharge or overflow ceases due to increased health risks from bacteria and other pollutants. A follow-up email will be distributed when these discharges have ceased. 

Blended Wastewater

Outfall ID Location Latitude Longitude Receiving Water Average Discharge Volume (MG) Discharge Start Time
035 LRWWU 42.6452 -71.28881 Merrimack River 6.64 9/18/23 1:13 pm

Combined Sewer Overflow Outfalls

Outfall ID Name Latitude Longitude Receiving Water Average Discharge Volume (MG) Discharge Start Time
002-SDS#1 Walker Station 42.6462 -71.3341 Merrimack River 2.17 9/18/23 8:40 pm
007-SDS#2 Beaver Brook 42.6593 -71.3193 Beaver Brook 1.16 9/18/23 7:53 pm
008-SDS#3 West Station 42.6525 -71.3103 Merrimack River 5.93 9/18/23 2:17 pm
011-SDS#4 Read Station 42.6482 -71.3011 Merrimack River 0.03 No Diversion
012-SDS#5 First Street 42.6476 -71.2909 Merrimack River 0 No Diversion
020-SDS#6 Warren Station 42.6428 -71.3050 Concord River 3.73 9/18/23 7:42 pm
027-SDS#7 Tilden Station 42.6507 -71.3115 Merrimack River 1.02 9/18/23 3:16 pm
030(1)-SDS#8 Barasford Station 42.6452 -71.2884 Merrimack River 2.75 9/18/23 3:15 pm
030(2) Merrimack Station 42.6452 -71.2888 Merrimack River 3.42 9/18/23 2:45 pm


See below for data on high flow management

CSO Report 2020
CSO Report 2021
CSO Report 2022
CSO Report 2023 YTD

High Flow Summary Report 2020
High Flow Summary Report 2021
High Flow Summary Report 2022

To view MassDEP Sewerage Notification Public Portal click here

Lowell Wastewater Outfalls